1. Field of the Invention
The present invention generally relates to methods, programs, and systems for verifying mask pattern data processes when generating mask patterns, and particularly relates to a method, program, and system for verifying an optical proximity correction process.
2. Description of the Related Art
In manufacturing of semiconductor devices, the pattern shape of a mask pattern is printed on a wafer by use of an optical transfer apparatus. As the miniaturization of semiconductor devices is further advanced, adjacent patterns may come in contact with each other because of an optical proximity effect. Further, corners of patterns may be rounded, and lines may become thinner and severed. By estimating such pattern deformation, the pattern data is processed such as to cancel or mitigate the deformation, thereby performing a correction process for ensuring that desired pattern shape is properly formed on the wafer. This is referred to as an optical proximity correction process.
The optical proximity correction process generates an aid pattern for mask pattern data in order to attain a desired wafer-transfer image by correcting the pattern on the reticle. Conventional pattern correction methods set rules with respect to the patters for correcting design data, and generate an aid pattern for reticle pattern data based on the rules for generating corrected patterns.
In order to check the pattern correction process as to whether it is satisfactory or unsatisfactory, a corrected pattern is generated for a simple predetermined test pattern. Visual inspection of this corrected pattern may then be carried out to see whether a desired pattern has been obtained. When the data is complex and its size is massive as in the case of an actual product, it is practically impossible to conduct visual inspection of the corrected pattern. Even when tools are used for verification, the results may not match each other, resulting in a large number of discrepancies, which makes the verification difficult.
[Patent Document 1] Japanese Patent Application Publication 2002-107908
Accordingly, there is a need for a verification method that can efficiently check whether optical proximity correction is properly working during the process of generating mask pattern data.